1. Field of the Invention
The present invention relates to the improvement of a unit for supplying solder balls or the like used in a mount apparatus for mounting solder balls, solder bumps or the like on a chip or a substrate. The invention was chiefly developed with the primary object of a solder ball supply unit in a BGA (Ball Grid Array) solder ball mount apparatus.
The present application is based on Japanese Patent Application No. Hei. 10-376863, which is incorporated herein by reference.
2. Description of the Related Art
In a BGA solder ball mount apparatus, solder balls are usually put in a ball tray, and picked up from the ball tray by a mount head. After picking up has been repeated, solder calls get fewer in the ball tray. As a result, the efficiency of suction onto the mount head is impaired, so that the Performance is reduced. Therefore, solder balls are usually supplied when solder balls in the ball tray get fewer than a predetermined amount. Since it is troublesome to supply solder balls by manual operation, a large-sized ball hopper is provided, and solder balls are supplied from the hopper to the ball tray by a required amount by their own gravity, compressed-air delivery or the like.
A background-art solder ball supply unit delivers solder balls forcibly. Therefore, when solder balls are supplied into a ball tray, compressed air or the like for supplying the solder balls blows into the ball tray so that disarray is caused in the ball tray. In such a manner, there used to arise scattering in the density of solder balls in the ball tray. It is therefore necessary to pause the running of the solder ball mount apparatus in order to level the density in the ball tray, so that there has been also a problem that the performance is reduced due to the pause of the running.